WGU D311 Microbiology Approved Exam Questions and Verified Correct Answers 2026 Series

WGU D311 Microbiology Approved Exam Questions and Verified Correct Answers 2026 Series Which vaccine type has the advantages of producing long-lasting cellular and humoral immunity and allowing transmission to contacts? live attenuated Broad-spectrum antibiotics disrupt the microbiome and provide an opportunity for pathogens such as Clostridium difficile to grow and cause infection. How can the microbiome be quickly reestablished to prevent a Clostridium difficile infection? fecal transplant When would it be best to treat a patient with a narrow-spectrum antimicrobial rather than a broad-spectrum antimicrobial? when the infectious agent has been identified as a gram-negative bacterium Which outcome is a direct result of the increased "leakiness" of capillaries during inflammation? edema Which describes a mutualistic relationship? Ruminococcus species using nutrients from a cow's diet to digest plant cellulose in the rumen Which viral virulence factor requires adjustments to the influenza vaccine annually? antigenic variation A bacterial pathogen is found growing in the bloodstream of a patient. Which diagnosis is correct for this finding? septicemia Why is desiccation or dehydration an effective method of microbial control? Water concentration decreases below what is required for microbial survival Which virulence factor produced by Pesudomonas aeruginosa gives off a fruity odor? pyocyanin A dental hygienist nicked the gum of the patient during a routine cleaning. A mild infection of the gum was followed 10 days alter with acute bacterial endocarditis. Which type of infection caused the endocarditis? a focal infection WGU D311 WGU D311 A student in a lab has just completed an endospore stain of Bacillus anthracis and realized that heat was not applied during the staining technique. What will the student see upon microscopic examination of the slide? pink vegetative cells with clear round areas Why are diseases like Legionnaires' disease considered noncommunicable? Once a person contracts this disease, they can not pass it to another person Why is there a resurgence in whooping cough and measles in the United States? more opposition to childhood vaccination What microbial process is used by bacteria and fungi to produce many common food products, such as soy sauce, bread, and yogurt? fermentation After oral antibiotic therapy, a patient is diagnosed with vaginitis. What type of microbe could be causing this opportunistic infection? fungus Which beneficial role do viruses have in the environment? integrating into plant genomes to increase drought tolerance A pregnant person has received all of her childhood immunizations, including for pertussis, but has chosen not to receive boosters while pregnant or to immunize her child once it is born. What will happen to her child if exposed to pertussis at five years old? The child's immune system will need to fight the infection indicates the presence of a primary pathogen rather than an opportunistic pathogen? patients with a healthy immune system What is the most common portal of exit for vector-transmitted diseases such as West Nile virus? blood Why is MRSA more pathogenic than other strains of Staphyloccocus aureus? MRSA has increased antibiotic resistance Which method of physical microbial control can be used to sterilize fresh food? radiation Which organism is implicated if type 1 fimbriae are used to attach to intestinal epithelial cells? Escherichia coli Which type of microbial control is used to remove most microbes from the kitchen counter in a restaurant? disinfection A technician has just performed a Gram stain but forgot to add the safranin. What is the likely result of this stain when viewed microscopically?: gram-negative organisms cannot be seen under the microscope What type of microbe is used to deliver gene therapies to human cells? WGU D311 WGU D311 virus How does coinfection of a single cell by multiple strains of a virus increase its pathogenicity? coinfection provides the opportunity for an antigenic shift Which class of cells most often contain extrachromosomal DNA found in plasmids? prokaryotic A person who is allergic to components of a vaccine is still protected from contracting a virus due to the vast majority of the surrounding population being vaccinated and unable to contract a pathogen. What is this phenomenon called? herd immunity When can narrow-spectrum antibiotics be used to treat infectious diseases effectively? when the infection is known to be caused by a gram-positive bacterium Why do aseptic techniques prevent contamination of a patient by microbes and infectious agents? Aseptic techniques maintain the sterility of an object or place through the use of physical and chemical protocols Which type of transmission describes a parent catching the common cold virus when caring for their sick child? direct contact transmission party for a niece, a person starts to develop fever, nausea, and vomiting. Within a day, nearly everyone who was in attendance has contacted this person, complaining that they are also sick. Family members who did not attend the party do not have these signs and symptoms. What is a likely explanation for how this disease spread? point source spread from a single contaminated food at the party A novel disease is epidemic in three countries. What should the World Health Organization do first to manage the spread? determine the etiologic agent How does filtration, such as that found in surgical masks, N95 respirators, and high efficiency particular air (HEPA) filters, prevent microbial transmission? filters have pores that trap particles above a certain size, including most microbes What is the significance of the molecule that makes up the bilayer formed in the plasma membrane of most bacterial and eukaryotic cells? Phospholipids help maintain hydrophobic and hydrophilic environments Which microorganisms can produce human pathogens that spread via microsporidia? fungi Why are photosynthetic bacteria and algae important to the carbon cycle on Earth? Photosynthetic microbes metabolize carbon dioxide, fix carbon, and produce oxygen Which statement regarding antiseptics are true? WGU D311 WGU D311 antiseptics kill microbes on skin or tissue via antimicrobial chemicals A patient recently had an outpatient surgical procedure. After a few days at home, they notice swelling and redness at their incision site. How would this infection be classified? iatrogenic To reach pathogens located in infected tissue, leukocytes must pass through the walls of small capillary blood vessels within tissues, a process that is called _________. extravasation Which microorganisms produce dermatophytes that can cause skin infections, such as athlete's foot and ringworm? fungi Which target would appropriately treat a fungal skin infection? ergosterol synthesis What type of diseases are found in higher numbers than expected in local populations? epidemic An infection by a pathogen that occurs several years after the first elicits a faster response from lymphocytes. Why is the response by lymphocytes to a second infection so much faster than the first? lymphocytes produce memory cells during the first infection, providing active immunity Canned food is heated and sealed in sterile containers to provide a longer shelf life and prevent spoilage. Improper canning results in the growth of microorganisms, which may result in food containers that swell and explode. Which staining technique can be used to identify these microorganisms? endospore staining Which organism type does a conjugate vaccine target? capsule-forming What role does contact tracing play in disease prevention? ensures that exposed individuals receive appropriate treatment and testing or isolate themselves An infected individual riding in a subway car coughs for a few minutes, then leaves. An individual standing at the opposite end of the car one hour after the infected individual left develops symptoms two days later. How was this pathogen transmitted? airborne transmission, where suspended mucus particles travel long distances over time to cause infection Which characteristic of mycobacterium makes a Gram stain unsuitable? the cell wall has a waxy lipid Why is ergosterol targeted by antifungals? Ergosterol synthesis allows for selective toxicity that is not possible with cholesterol WGU D311 WGU D311 A patient presents with an infection on an implant. What should the clinician consider in planning the treatment course? The infection is likely a biofilm, causing a physical barrier to antibiotics Why are archaea considered prokaryotic organisms? Their cells do not contain a nucleus WGU D311